Malicious PDF — malware analysis report

Static analysis result for SHA-256 550bb324bd697a33…

MALICIOUS

PDF

105.5 KB Created: 2021-09-18 13:00:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a1adc4ec0713d1632976a124c8192d92 SHA-1: bbddb6c7bc34592a8836e196ded5d97f06e9a761 SHA-256: 550bb324bd697a3372d45945e7b84f18a6159086a5329f31c528b64e45f25f20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The ML classifier and ClamAV also identified it as malicious. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest the document's purpose is to redirect users to malicious websites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/02142adf586f37c1de6991f3547727e1/76665228766.pdf In PDF document text
    • https://shriayurvednagpur.org/public/ckfinder/userfiles/files/82468099176.pdfIn PDF document text
    • http://vp-dmsh.ru/admin/ckfinder/userfiles/files/28241872494.pdfIn PDF document text
    • https://tapetcenter.ro/app/webroot/files/userfiles/files/suvafamadoxek.pdfIn PDF document text
    • http://oilmachineydy.com/d/files/41508576488.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613850d10b98c---35027788253.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/90008276458.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/92598456846.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/dezuraz.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/72763984285.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca87647b52---73300546935.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/puwalupalukofukirotovo.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/lerezi.pdfIn PDF document text
    • https://5a.ro/ckfinder/userfiles/files/86231359623.pdfIn PDF document text
    • http://hsaltsj.com/uploads/files/28237418559.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161370de3ef2cb---kovejoxefilivadatofir.pdfIn PDF document text
    • http://jonellchem.com/upload/files/zexorixakudu.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/eef0b72985e1aef95f40b190f3bf8a5f/21953653040.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/11522846113.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/samilivafotukodasebukopu.pdfIn PDF document text
    • http://hebakotb.net/userfiles/file/wonazawobusowukudagaj.pdfIn PDF document text
    • https://hilanguage-com-tw.triangle-design.com/files/kofegevivu.pdfIn PDF document text
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/48980087481.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=long+o+soundPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013c35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C35 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15447 18088 bytes
SHA-256: 83ed55866615fd5272e014124bea9f6001130d47c6ce2712ecb59f1b05c63dc7
font_02_sfnt_off0001835d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1835D 9848 bytes
SHA-256: 49e90a31cd8f781aa46f21ba1bacd3154339b68e779ad293686ab61dc55fcc87